fix: commit cache

src/lib.rs

@@ -85,10 +85,14 @@ impl Client {
     }
 
     pub fn save_cache(&self, key: &CacheKey, cache: Vec<u8>) -> Result<()> {
-        let cache_id = self.reserve(key, cache.len()).context("reserving cache")?;
+        let cache_len = cache.len();
+        let cache_id = self.reserve(key, cache_len).context("reserving cache")?;
 
         self.save(cache_id, cache).context("saving the cache")?;
 
+        self.commit_cache(cache_id, cache_len)
+            .context("committing the cache")?;
+
         Ok(())
     }
 
@@ -169,6 +173,38 @@ impl Client {
         Ok(())
     }
 
+    fn commit_cache(&self, id: CacheId, cache_size: usize) -> Result<()> {
+        let uri = format!("{}_apis/artifactcache/caches/{}", self.base_url, id.0);
+        let request = Request::builder()
+            .uri(uri)
+            .method(Method::POST)
+            .body(
+                serde_json::json! {{
+                    "size": cache_size,
+                }}
+                .to_string(),
+            )
+            .context("building the request")?;
+        let mut response = self
+            .http_client
+            .send(request)
+            .context("sending the request")?;
+        let status = response.status();
+        if status != StatusCode::OK {
+            let mut body = Vec::with_capacity(100);
+            response
+                .body_mut()
+                .read_to_end(&mut body)
+                .context("reading response body")?;
+            bail!(
+                "Failed reserving a cache (status {status}): {:?}",
+                String::from_utf8_lossy(&body)
+            );
+        }
+
+        Ok(())
+    }
+
     pub fn load_cache(&self, key: &CacheKey) -> Result<Option<Box<[u8]>>> {
         let Some(cache_location) = self.get_cache_entry(key).context("getting cache entry")? else {
             // cache miss